A navigation system searches for a route on the basis of destination information such as an address, a name, and a phone number for specifying a destination and current position information. A navigation system generally includes an access device to a portable recording medium, reads map data and spot information representing a spot on a map from the portable recording medium, and searches for a route. Some navigation systems may provide supplementary information such as recommended foods information of restaurants at the time of guidance on a route. Since such supplementary information varies more frequently than the map data of roads and the like, means for providing the latest supplementary information is necessary in addition to the recording medium. For example, PTL 1 proposes a navigation system providing the latest supplementary information by communications.